Abstract The sintering process of nanometric undoped SnO 2 powder was studied. No macroscopic shrinkage was observed during the sintening process. Grain growth kinetics investigation showed that surface diffusion is the dominant mechanism in the temperature range 500–1300°C. For temperatures higher than 1300°C, high weight loss was measured, suggesting evaporation–condensation as the dominant mass-transport mechanism. Thermogravimetric analysis (TG) and mass spectroscopy studies showed that the surface contamination of the SnO 2 particles by chemical species like H 2O, OH − and CO 2, has a strong influence on the role of mass transport controlled by surface diffusion.